Introduction and Aims: Hip resurfacing has undergone a resurgence of interest in the past five years, requiring surgeons to learn new principles and new operative techniques. For experienced surgeons, the learning curve is more transparent than in their earlier careers.

Method: We have reviewed the first 100 hip resurfacings performed by two experienced surgeons. Results of the first 20 and second 20 were compared for a difference, then the first 30 and second 30 and finally the first 50 and second 50. We evaluated accuracy of pre-operative planning to final sizing, pre-operative neck shaft angle and post-operative prosthesis angle, revision rates, complication rates, equipment problems, placement of the acetabular component.

Results: On comparing the first 50 procedures performed with the second 50 performed, there was a significant difference (p< 0.001) in positioning of the femoral prosthesis, notching of the femoral neck, seating of the femoral and acetabular component position and seating. When comparing the first 20 and second 20 procedures no significant difference was noted.

Conclusion: We note there is a definite learning curve associated with the hip resurfacing procedure and it was longer than we estimated.

Introduction: Hip resurfacing has undergone a resurgence of interest in the past five years. With it, the awareness of femoral neck fractures associated with this prosthesis has grown. We report the first national review of femoral neck fractures over a four-year period.

Method: All surgeons using the Birmingham hip resurfacing in Australia were contacted and asked to supply details of any femoral neck fractures they had experienced. Routine co-morbidities and demographics were collated.

Results: Fifty fractures have occurred in the time period. The fracture rate was twice as high in women than men and this was statistically significant (p< 0.001). Mean time to fracture was 15 weeks and was slightly longer in women than men. Technical difficulties included notching of the femoral neck, varus placement of the femoral prosthesis, poor exposure due to obesity and poor impaction of the femoral component.

Conclusions: The national fracture rate associated with the Birmingham hip resurfacing is 1.46%.

Introduction: Over the past decade metal on metal bearings in the form of hip resurfacings have been increasing in popularity and with it an associated interest in the potential side effets of elevated serum metal ion levels.

Methods: We prospectively measured the cobalt and chromium serum levels of 20 patients over a 2 year period following Birmingham hip resurfacing. Cobalt was measured with inductively coupled plasma mass spectrometry and chromium using graphite furnace atomic absorption spectrometry.

Results: For serum cobalt there was an initial increase to a peak at 6 months then a gradual decline. A similar pattern was observed for chromium, although the peak occurred slightly later at 9 months.

Conclusions: One off single measurements of metallic ion levels are of minimal clinical use, when the actual pattern of ion elevation and fall is not known. This study allows us to expect a peak at certain times following a hip resurfacing and a gradual decline thereafter.

220 consecutive hip resurfacing procedures were reviewed at a minimum of two years follow up to assess the incidence of heterotopic ossification and its effect on function and clinical outcome. We also reviewed the pre-operative diagnosis, gender and previous surgery. The overall percentage of heterotopic ossification was 58.63%. The incidence of Brooker 1 was 37.27%, Brooker 2 was 13.18% and Brooker 3 was 8.18%.

Male osteoarthritics had the highest incidence of heterotopic bone formation. Three males underwent excision of heterotopic bone, two for pain and stiffness and one for decreased range of movement.

Both antero-posterior and lateral radiographs were reviewed for evidence of heterotopic bone formation. 12.7% had no evidence of heterotopic bone formation on one view but clearly had on the second view.

Overall we found no evidence that heterotopic bone formation affected the clinical or functional outcome of the hip resurfacing at a mean of 3 years follow up.

We describe our early experience with the implantation of the first consecutive 231 primary Birmingham Hip resurfacings. At a mean follow up of 33 months, survivorship was 99.14 %, with revision in one patient for a loose acetabular component and one unrelated death.

Mean Harris Hip score improved from a mean of 62.54 ( Range : 8–92) to 97.74. (Range: 61 – 100) Mean flexion improved from a mean of 91.52°, ( Range : 25° –140°) to a mean 110.41°. ( Range : 80° – 145°)

1 patient presented at 6 weeks post resurfacing with pain and no history of trauma. An undisplaced fracture of the superior femoral neck was seen, which healed with a period of non-weight bearing.

96.94% of patients rated their prosthesis as good / excellent, the remainder rated it good/fair.

Introduction: Hip resurfacing has undergone a resurgence of interest in the past 5 years. This has required the acquistion of new surgical principles and techniques. Allowing us to study the learning curve associated with acquiring these skills.

Methods: The first 50 hip resurfacings and the second hip resurfacings performed by two consultant surgeons were compared for femoral fit, pre-operative femoral neck shaft angle, post-operative prosthesis angle, acetabular cup abduction angle, seating of the acetabular component, post-operative complications and revision rates.

Results: There was a statistically significant improvement in the alignment of acetabular components, seating of the acetbaular component and fewer problems associated with the acetabular introducer in the second cohort. There was more consistent placement of the femoral prosthesis in the neck,less notching and less variation in position in the second cohort.

Conclusions: There is a definite leaning curve associated with hip resurfacing and it was longer than expected.

We describe the experience with the first consecutive 230 Birmingham hip resurfacings at our centre. At a mean follow-up of three years (25 to 52 months) survivorship was 99.14% with revision in one patient for a loose acetabular component and one death from unrelated causes. One patient developed a fracture of the femoral neck at six weeks which united unremarkably after a period of non-weight-bearing. The Harris hip score improved from a mean of 62.54 (8 to 92) to 97.74 (61 to 100). The mean flexion improved from 91.52° (25 to 140) to 110.41° (80 to 145).

Most patients (97%) considered the outcome to be good or excellent. Our preliminary experience with this implant is encouraging and the results are superior to the earlier generation of resurfacings for the same length of follow-up.

Aim: To review the efficacy of Osteogenic Protein-1 (OP-1; BMP-7) in treating non-unions of fractures of the long bones.

Method: Twenty-eight patients who had previously had non-unions of long bone fractures treated unsuccessfully by conventional methods were entered into the study. OP-1 was used with autograft in 22 cases (OP-1 Implant is composed of 3.5mg OP-1/1g bovine bone collagen). The author reviewed all x-rays and, with the assistance of the 21 treating surgeons, assessed the clinical outcomes.

Results: There had been an average of 3.1 (median = two, range: one to 12) previous procedures and 24.3 months (median = 22 months, range: five to 84 months) since the injury. Twenty of the non-unions were diaphyseal and eight were metaphyseal. Seventeen of the 28 patients had some alteration to internal fixation. Nine patients had significant concomitant conditions. On clinical examination, 20 fractures had united, three were unable to be assessed and five had failed. The average time to union was 5.6 months (range: three to 15 months). When the x-rays were reviewed 21 had united. Two were unable to be assessed and five had failed. There were no adverse events or complications that can be attributed to the use of OP-1.

Discussion: This is a follow up of 28 difficult cases which had failed to respond to the current gold standard for treating recalcitrant non-unions. The contribution made by alteration of fixation needs to be recognised. Irrespective of this fact, there had been an average of 3.1 previous bony procedures involving grafting and changes of fixation.

Conclusion: OP-1 initiates bone formation in humans, it appears to be safe and may potentiate the action of autograft. The results for this group of recalcitrant cases suggested that it had been useful in obtaining successful outcomes for these patients who had failed to unite their fractures after traditional techniques had been used.